miRNA-765 mediates multidrug resistance via targeting BATF2 in gastric cancer cells.

Elucidation of the mechanisms underlying multidrug resistance (MDR) is required to ensure the efficacy of chemotherapy against gastric cancer (GC). To investigate this issue, here we identified that microRNA-765 (miRNA-765) is upregulated both in MDR GC cell lines and in specimens from patients not responding to chemotherapy. In addition, downregulation of miRNA-765 increased the sensitivity of GC cells to anticancer drugs, while its over-expression had the opposite effect. Moreover, miRNA-765 suppressed drug-induced apoptosis and positively regulated the expression of MDR-related genes. Finally, we showed that the basic leucine zipper ATF-like transcription factor 2 (BATF2), a tumor suppressor gene, is the functional target of miRNA-765. In summary, these results suggest that miRNA-765 may promote MDR via BATF2 in GC cells.